diff options
| author | Richard Guenther <rguenther@suse.de> | 2011-12-05 14:31:44 +0000 |
|---|---|---|
| committer | Richard Guenther <rguenther@suse.de> | 2011-12-05 14:31:44 +0000 |
| commit | 7c5066e7bbfcc6e0871ea34161e9cd871fbe4293 (patch) | |
| tree | 337d4dd6961a88c69b24dda561d596121394e7e4 /gcc/tree-ssa-alias.c | |
| parent | 170c1f10f7d32cc5cec5671a000ef4160a6b1ca8 (diff) | |
2011-12-05 Richard Guenther <rguenther@suse.de>
* tree-ssa-alias.h (struct ao_ref_s): Add volatile_p field.
* tree-ssa-alias.c (ao_ref_init): Initialize it.
(ao_ref_init_from_ptr_and_size): Likewise.
(refs_may_alias_p_1): Two volatile accesses conflict.
(ref_maybe_used_by_call_p_1): Likewise.
(call_may_clobber_ref_p_1): Likewise.
* tree-ssa-sccvn.c (ao_ref_init_from_vn_reference): Initialize
volatile_p field.
git-svn-id: https://gcc.gnu.org/svn/gcc/trunk@182009 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/tree-ssa-alias.c')
| -rw-r--r-- | gcc/tree-ssa-alias.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c index cd222093579..21dc5fbcc51 100644 --- a/gcc/tree-ssa-alias.c +++ b/gcc/tree-ssa-alias.c @@ -456,6 +456,7 @@ ao_ref_init (ao_ref *r, tree ref) r->max_size = -1; r->ref_alias_set = -1; r->base_alias_set = -1; + r->volatile_p = ref ? TREE_THIS_VOLATILE (ref) : false; } /* Returns the base object of the memory reference *REF. */ @@ -525,6 +526,7 @@ ao_ref_init_from_ptr_and_size (ao_ref *ref, tree ptr, tree size) ref->max_size = ref->size = -1; ref->ref_alias_set = 0; ref->base_alias_set = 0; + ref->volatile_p = false; } /* Return 1 if TYPE1 and TYPE2 are to be considered equivalent for the @@ -1021,6 +1023,11 @@ refs_may_alias_p_1 (ao_ref *ref1, ao_ref *ref2, bool tbaa_p) || TREE_CODE (base2) == LABEL_DECL) return true; + /* Two volatile accesses always conflict. */ + if (ref1->volatile_p + && ref2->volatile_p) + return true; + /* Defer to simple offset based disambiguation if we have references based on two decls. Do this before defering to TBAA to handle must-alias cases in conformance with the @@ -1144,6 +1151,11 @@ ref_maybe_used_by_call_p_1 (gimple call, ao_ref *ref) if (!base) return true; + /* A call that is not without side-effects might involve volatile + accesses and thus conflicts with all other volatile accesses. */ + if (ref->volatile_p) + return true; + /* If the reference is based on a decl that is not aliased the call cannot possibly use it. */ if (DECL_P (base) @@ -1477,6 +1489,11 @@ call_may_clobber_ref_p_1 (gimple call, ao_ref *ref) || CONSTANT_CLASS_P (base)) return false; + /* A call that is not without side-effects might involve volatile + accesses and thus conflicts with all other volatile accesses. */ + if (ref->volatile_p) + return true; + /* If the reference is based on a decl that is not aliased the call cannot possibly clobber it. */ if (DECL_P (base) |